To conserve energy, today most of the portable, wearable, wireless sensor network and other electronic products are designed to be low in power consumption and compact in size. Conventionally, memory usually consumes a major part of power and occupies space of a system chip; and therefore, effective reduction of power consumption and size of memories have been a challenging issue in designing electronic products.
To solve the problems and improve conventional memories, resistive content addressable memory cell was developed. In general, resistive content addressable memory cell is widely used for data comparison in portable, wearable, wireless sensor network and other electronic products. In addition, as one of the newly-developed non-volatile memories, resistive content addressable memory is able to compare permanent reference more effectively due to their high data writing speed, low power consumption, high area density and compatible CMOS process.
However, conventional resistive content addressable memory cells require the use of dual voltage source; therefore, an extra charge pump or other voltage conversion circuit would be necessary. As a result, the circuit area as well as the time and power consumption for data writing and search operations are increased. Thus, there is a need to develop a content addressable memory to overcome the aforementioned problems.